This bulletin from the Reserve Bank of New Zealand asks whether it makes sense for a central bank to issue either a cryptocurrency or a more conventional digital currency. Whether they end up doing so or not, it’s notable a major central bank is actually considering the idea openly.
The report doesn’t reveal the central bankers’ real motivation. Eliminating physical cash would make a negative interest rate policy far more feasible. No more going to the ATM and being able to withdraw because cash wouldn’t exist anymore. And the banks would be able to freeze your accounts if you wanted to transfer your money electronically somewhere else. With other policy tools losing their effectiveness, the RBNZ and its peers (Fed, BoJ, RBA, etc.) may be trying to open a path to NIRP. This report is one tiny step in that direction.
https://www.rbnz.govt.nz/research-and-publications/reserve-bank-bulletin/2018/rbb2018-81-07